Carbureter



0 t. M w M ad F. A. LUCAS.

CARBURETER.

APPLICATION FILED Nov. s. 1918.

Patented Feb. 15, 1921.

UNITED STATES FRANK A. LUCAS, OF DETROIT, MICHIGAN.

CARBURETEB.

Specification of Letters Patent.

Patented Feb. 15, 1921.

Application led November 8, 1918. Serial No. 281,604.

To all whom it may concern.:

Be it known that I, FRANK A. LUCAS, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Carbureters, of which the following is a Specification, reference being had therein to the accompanying drawings.

The object of my invention is to simplify the construction and cheapen the cost of carbureters, and at the same time provide a more eflicient carbureting device that may be characterized in the following particulars.

First, the carbureter includes a \station ary Venturi member and a valvular member movable relative to said Venturi member, said valvular member obviating the necessity of using the ordinary throttle or butterily valve in the upper portion of the carbureter.

Second, there is an annular fuel outlet port positioned in proximity to the Venturi and valvular members so that there is a constant annular source of fuel that may be withdrawn for admixture with air, this constantly open source of fuel being in contradistinction to a valve regulated supply and a supply delivered at a multiplicity of places relative to the Venturi member or the mixing chamber of the carbureter.

Third, the carbureter includes a novel by-path construction which permits of sufficient fuel being withdrawn from the supply for engine idling purposes when air is shut off or approximately so to the carbureter.

Fourth, the carbureter is characterized by a mechanical construction consisting of comparatively few parts, easy to assemble and of such a nature as to be properly proportioned for a duty predetermined in connection with any engine, thus obviating the necessity of using one make of carbureter for one type of engine. With my carbureter it is only necessary, in the initial assembling, to properly position the Venturi member relative to the constantly open fuel supply ort.

p The above is a brief outline of the main features of my invention, and reference will now be had to the drawing, wherein- Figure 1 is a vertical longitudinal sectional view of the carbureter, and

Fig. 2 is a horizontal sectional view of a portion of the same taken on the line II-II of Fig. 1.

In describing my invention by aid of the vlews above referred to it is to be understood that the structural elements are illustrated merely as an example of the preferred form of the carbureter, and that the construction entering into the same is susc eptible to such modifications and variatlons as are necessary to render the earbureter efficient for a particular duty.

In the drawing, the reference numeral 1 denotes an air intake elbow connection which has the lower or outer endthereof J10 fuel is maintained within the float chamber.

The upper end of the air intake yeonnd tion 1 is provided with an annulartpped' recess 9 and the inner end of said recess affords an annular' shoulder or seat 10 for the inner end of a cylindrical shellf or wall member 11 that coperates with the annuler wall of the recess 9 in providing fan annuler fuel holding channel or port ,12 which y is constantly open and receives fuel' the float chamber 3 through the mediumof porte 13 and 14. The port 13 has its-upper end opening into the channel 12 and its lower end communicating with the port 14,said port being in the lower part of the Hoet chamber 3 to receive fuel when the needle valve 5 is properly adjusted., Thel Hoet" chamber, to ther with its communicating ports, constltutes a source of fuel supply for the carbureter and means for maintaining a constant level of fuelwithin the channe 12. Mounted on top of the air intake nection 1 is a casing providing chamber 15 having a' dependingend portion` 16 the recess 9 of the air nextending into take connection 1 and restrictmg the ebannel 12 relative to the wall member' 11, so as to provide a narrow annular port at the upper edge of the wall member 11, saidiport having for its inner wall the sleeve or wall member 11 and for its outer wall an end portion 16 of the mixing chamber 15, particularly at the juncture of the end portion k16 and the mixing chamber 15. As clearly shown in Fig. 1 the greater portion of said port is vertical and its upper end terminates in a small lateral portion circumferentially'of the upper edge of the sleeve or 'i wall member 11.

Fixed in the mixing chamber 15 is a Venturi member 17 providing an annular seat 18 iii proximity to the lowerfend of the mixing chamber. This Venturi member is ported, as at 19, to receive communicating by-path tubes 20 and 21, the former extending into the upper portion of the Venturi member 17, above ythe seat 18, and the latter depending from the seat 18 into the eiidportion 16 of the mixing chamber. The lower end of the by-path tube 21 is bent so as to confront the outer wall of the annular fuel port, designated 22, so that fuel may y Vbe withdrawn from said port and discharged .into the upper portion ofthe Venturi member 17 v Suitably mounted in the air intake connection 1 is a post 23 that is concentric of the sleeve or wall member 11 and in the axis of the mixing chamber 15. The'post may have its lower end conveniently attaclied to the air intake connection 1, as at 24, and its upper end is adapted to extend into theupper portion of the Venturi member 17. Slidable on said post is the sleeve v'or tubular guide membery25 of a throttle or valvular member 26, which is preferably hollow. The valvular member 26V for the greater part of its Vlength is cylindrical so as to coperate with the sleeve or wall member 11'in providingV an annular passage leading past the annular port 22into the lower end vof the Venturi member 17 and the upper end ofsaid valvular member is conicalor "tapered so as to concentrically engagey the seat 18 and shut off the main supply of 'fuel throughl the Venturi member 17, without interfering with the auxiliary supply throughthe by-path tubes 20aiid 21 @for engine idling purposes.

IExtending into the lower end of the air intake connection 1 and through ,suitable `bearings 27 provided therefor, is a rock shaft 28 having inner and outer crank portions 29 and 80, the latter permitting of the shaft v28 being rocked or adjusted. The inner crank portion 29 is loosely connected to a head 31 on the-.lower end of the sleeve or tubular guide 25 of the valvularmember 26, the elements 27 and 31 inclusive constituting means operatable at the air .intake con- Hnection land below the valvular member vannular constantly opeii fuel port 22 is in of the Venturiy member 17 and is directed S0 toward a vortex in the upper portion of the YVenturi member which constitutes aV mixing chamber and insures a thorough commingling of fuel and air'due to the seat 18 of the .Venturi vmember 17 and the upper end of the valvular member 26 directing the fuel to the axis of the mixing chamber 15. Thisis particularly true when the valvular member 26 is wide open with the engine producing a high velocity of air past the open port 22, whereas with the valvular member 26 slightly off of the seat 18 the fuel has a chance to spread in the upper portion of the'Venturi member and thus prevent stratification of air and fuel in the mixing chamber. f A

The 'constantly open fuel port 22V has the advantageover a plurality of orifices in presenting a large surface of gasolene or other fuel tothe all', so as tobe attacked 100 thereby, besides vbeing easier and cheaper to v produce than small drilled or otherwise formed orifices. f

I attach considerable importance Yto the fact -that the Venturi member 17 is sta- *105 tionary and fixed in the mixing chamber 15 so as to have a defined position relative to the endy portion -16 of the mixing chamben'such position being determined and made nonadjustable according to the duty to be performed by the carbureter. This is also true inconnection with thesleeve or wall mein-l ber 11 which may be of a height to coperate with the mixing chamber in providing the fuel port 22 Vwith an lopening of sufcient 115 area so as not to retard the withdrawal of fuel from the channel 12. In other words, one .make of engine may require a fuelport of more or less area than another make of engine and after such is determined, the

. sleeve or wall member is provided which will and from'the member 17 and in actual practice, the vstationary member 17 saves material and obviates connections that would be necessary V.ifit were/movable relative to 130 the valve member. It is now apparent that the carbureter consists of ve few adjustable parts, which is a desi eratum especially in connection with carbureters for air crafts. After my carbureter is once installed and properly adjusted there is only one adjustment, that of the valvular member 26 and this materially simplifies an intelligent operation of a motor by vehicle or air craft, as far as fuel supply is concerned. Again, use of a fuel port of the particular type herein employed standardization of parts may be attained and, as pointed out before, the only possible differentiation may be in the position of the Venturi member 17 with reference to the annular fuel port 22 and in connection with the sleeve or wall member 11, which may be made of various depths with each depth to coperate with the carbureter in producing a known result with a known type of engine. I am aware that a great many carbureters have been invented having shiftable Venturi members, valved fuel ports, throttles and other adjustable elements, all necessitating specializing, expensive manufacture and considerable exerience before desired results are attained.

roadly, I aim to eliminate complication and expense of manufacture by my improved carbureter.

A carbureter comprising an air intake connection, a casing thereon providing a miXinOr chamber, a fixed Venturi member in sai casing providing a valve seat, a cylindrical shell carried by said air intake connection and extending 1nto the lower end of the mixing chamber of said casing and coperating with said air intake connection and the lower end of said casing in providing a constantly open fuel port, means adapted to supply fuel to said port, and a cylindrical valve having a conical end movable to and from the valve seat of said Venturi member and constantly presenting a wall toward the fuel port to coperate with said c lindrical shell in providing a passage l ing past said fuel port, said valve controlling the outlet of the mixture from the carbureter.

In testimony whereof I aix my signature in the presence of two witnesses.

FRANK A. LUCAS.

Witnesses KARL H. BUTLER, ANNA M. Donn. 

